Optical fiber connection system including optical fiber alignment device with optical fiber cleaner

ABSTRACT

The present disclosure relates to system and method for cleaning an end face of a bare optical fiber (100). The system and methods include inserting the end face of the bare optical fiber (100) through a layer of material (500) that includes electrospun fibers.

This application is a Continuation of U.S. patent application Ser. No.15/687,665, filed on 28 Aug. 2017, now U.S. Pat. No. 10,578,810, whichis a Continuation of U.S. patent application Ser. No. 14/764,494, filed29 Jul. 2015, now U.S. Pat. No. 9,885,839, which is a National StageApplication of PCT/EP2014/051711, filed 29 Jan. 2014, which claimsbenefit of U.S. Provisional Application Ser. No. 61/758,150, filed 29Jan. 2013 and U.S. Provisional Application Ser. No. 61/885,850, filed 2Oct. 2013 and which applications are incorporated herein by reference.To the extent appropriate, a claim of priority is made to each of theabove disclosed applications.

TECHNICAL FIELD

The present disclosure relates to optical fiber connection systems andto devices and methods for aligning two fibers end-to-end.

BACKGROUND

Modern optical devices and optical communications systems widely usefiber optic cables. Optical fibers are strands of glass fiber processedso that light beams transmitted through the glass fiber are subject tototal internal reflection wherein a large fraction of the incidentintensity of light directed into the fiber is received at the other endof the fiber.

Many approaches to achieve fiber alignment can be found in the priorart, among them are V-grooves and ferrules. Ferrule based alignmentsystems including include ferruled connectors which use cylindricalplugs (referred to as ferrules) that fit within an alignment sleeve(e.g., a cylindrical split sleeve with elastic characteristics) toperform fiber alignment. Precision holes are drilled or molded throughthe centers of the ferrules. Optical fibers are secured (e.g., potted)within the precision holes with polished ends of the optical fiberslocated at end faces of the ferrules. Precise fiber alignment depends onthe accuracy of the central hole of each ferrule. Fiber alignment occurswhen two ferrules are inserted into an alignment sleeve such that theend faces of the ferrules oppose one another and the optical fiberssupported by the ferrules are co-axially aligned with one another.Normally, ferruled connectors use ceramic or metal ferrules in which theprecision center holes are drilled. Disadvantageously, drilling of sucha central hole that is accurate enough for aligning can be difficult. Inaddition, a connector containing a ferrule has very high manufacturingcosts. Therefore looking for adequate alignment solutions containingferrule-less connectors would be more desirable.

V-grooves are commonly used in prior-art ferrule-less fiber opticalignment devices. An example is the V-groove method described in U.S.Pat. No. 6,516,131 used for alignment of optical fiber ends. TheV-groove is uni-directionally or bi-directionally tapered for enablingeasy positioning of the fibers. Optical fibers are pressed into theV-grooves and line contact between the optical fibers and the surfacesof the V-grooves assists in providing precise alignment of the opticalfibers. In one example, two optical fibers desired to be opticallyconnected together are positioned end-to-end within a V-groove such thatthe V-groove functions to co-axially align the optical fibers. End facesof the aligned optical fibers can abut one another.

For optical couplings to be effective, it is important for the end facesof the optical fiber being coupled together to be clean. Improvementsare needed in this area.

SUMMARY

One aspect of the present disclosure relates to structures and methodsfor cleaning optical fibers. In certain examples, the cleaningstructures can be incorporated into optical fiber alignment devicesconfigured for co-axially aligning two fibers end-to-end. In certainexamples, the cleaning structures can be incorporated into mechanicalsplicing devices. In certain examples, the cleaning structures can beincorporated into fiber optic adapters. In certain examples, thecleaning structures are configured to clean (e.g., remove particulate,liquid, and/or other contaminants) from an optical fiber.

In certain examples, the cleaning structures are configured to inhibitcontaminants from entering an alignment device. For example, an opticalfiber can be plugged into a first adapter port and pierce a cleaningstructure at a first end of an optical fiber alignment device while anopposite adapter port remains empty. In such an example, a cleaningstructure at an opposite end of the alignment device can inhibitcontaminants from entering the alignment device and/or contaminating theoptical fiber received at the first end of the alignment device.Accordingly, in certain implementations, dust caps need not be disposedat the empty ports.

In certain examples, the cleaning structures are configured to inhibitgel (e.g., a thixotropic gel) disposed within the alignment device fromexiting the alignment device. In an example, a cleaning structure can beconfigured to retain the gel within the alignment device while anoptical fiber end face pierces the cleaning structure and enters thealignment device. In another example, a cleaning structure can beconfigured to retain the gel within the alignment device while anoptical fiber end face is removed from the cleaning structure and fromthe alignment device.

In certain examples, the cleaning structures are configured to inhibitlight emitted from an end face of an optical fiber from exiting astructure (e.g., an optical adapter) through an empty port. For example,a cleaning structure disposed at a first end of an alignment device mayinhibit light from an optical fiber received at an opposite end of thealignment device from leaving the alignment device until another opticalfiber is received at the first end.

In certain examples, the cleaning structures can include fiber cleaningsheets having self-healing characteristics. In certain examples, thecleaning structures are electrically charged. In an example, thecleaning structures can be electrically charged by mixing a solution tobe electrospun with a surfactant salt, such as CETAB(cetyltrimethylammoniumbromide). In an example, the cleaning structurescan be electrically charged by a surface modification technique, such asa plasma treatment. In certain examples, the cleaning structures includefabric or sheeting that includes electrospun fibers.

The term “optical fiber” as used herein relates to a single, opticaltransmission element having a core and a cladding. The core is thecentral, light-transmitting region of the fiber. The cladding is thematerial surrounding the core to form a guiding structure for lightpropagation within the core. In certain implementations, the core andcladding can be coated with a primary coating usually comprising one ormore organic or polymer layers surrounding the cladding to providemechanical and environmental protection to the light-transmittingregion. In certain implementations, the core, cladding, and optionalprimary coating can be coated with a secondary coating, a so-called“buffer”, which is a protective polymer layer without optical propertiesapplied over the primary coating.

The core can have a diameter of about 200 nm to about 20 μm. In certainimplementations, the core can have a diameter of about 5-10 μm. Incertain implementations, the core can have a diameter of about 8-12 μm.In certain implementations, the cladding can have a diameter of about120-130 μm. The primary coating may have a diameter ranging e.g. between200 and 300 μm. The buffer or secondary coating usually has a diameterranging between 300-1100 μm, depending on the cable manufacturer.

The term “light” as used herein relates to electromagnetic radiation,which comprises a part of the electromagnetic spectrum that isclassified by wavelength into infrared, the visible region, andultraviolet.

Index matching gel can be used with alignment devices in accordance withthe principles of the present disclosure to improve the opticalconnection between the open light transmission paths of the first andsecond optical fibers. The index matching gel preferably has an index ofrefraction that closely approximates that of an optical fiber is used toreduce Fresnel reflection at the surface of the bare optical fiber ends.Without the use of an index-matching material, Fresnel reflections willoccur at the smooth end faces of a fiber and reduce the efficiency ofthe optical connection and thus of the entire optical circuit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an optical fiber alignment device inaccordance with the principles of the present disclosure;

FIG. 2 is another perspective view of the optical fiber alignment deviceof FIG. 1;

FIG. 3 is a further perspective view of the optical fiber alignmentdevice of FIG. 1;

FIGS. 4-6 are exploded views of the optical fiber alignment device ofFIG. 1;

FIG. 7 is a cross-sectional view taken along section line 7-7 of FIG. 2;

FIG. 8 is a top view of the optical fiber alignment device of FIG. 1with a clip of the optical fiber alignment device removed;

FIG. 9 is a cross-sectional view taken along section line 9-9 of FIG. 7with the clip removed;

FIG. 10 is an end view of the optical fiber alignment device of FIG. 1;

FIGS. 11 and 12 show a connector in which the optical fiber alignmentdevice of FIG. 1 has been incorporated;

FIG. 13 is a perspective view of a duplex fiber optic adapter in whichtwo optical fiber alignment devices of the type shown at FIG. 1 havebeen incorporated;

FIG. 14 is an end view of the duplex fiber optic adapter of FIG. 13;

FIG. 15 is a top view of the duplex fiber optic adapter of FIG. 13;

FIG. 16 is a cross-sectional view taken along section line 16-16 of FIG.15;

FIGS. 17 and 18 show a simplex fiber optic adapter in which one of theoptical fiber alignment devices of FIG. 1 has been incorporated;

FIG. 19 shows the simplex fiber optic adapter of FIGS. 17 and 18 withfiber optic connectors inserted therein;

FIG. 20 illustrates a fiber optic connector in a non-connected state;

FIG. 21 illustrates the fiber optic connector of FIG. 20 in a connectedstate;

FIG. 22 is a front, top, perspective view of the fiber optic connectorof FIG. 20 with a shutter of the fiber optic connector in a closedposition;

FIG. 23 is a front, bottom, perspective view of the fiber opticconnector of FIG. 22 with the shutter in the closed position;

FIG. 24 is a front, top, perspective view of the fiber optic connectorof FIG. 20 with a shutter of the fiber optic connector in an openposition;

FIG. 25 is a front, bottom, perspective view of the fiber opticconnector of FIG. 22 with the shutter in the open position;

FIG. 26 is an exploded view showing a fiber optic adapter and aconverter for converting the fiber optic connector of FIG. 20 to aferruled fiber optic connector;

FIG. 27 is an exploded view of the converter of FIG. 26;

FIG. 28 is an assembled view of the converter of FIG. 27;

FIG. 29 is a cross-sectional view of the converter of FIG. 28;

FIG. 30 is a cross-sectional view of the converter of FIG. 29 with thefiber optic connector of FIG. 20 inserted therein;

FIG. 31 is a top view of the duplex fiber optic adapter of FIG. 13;

FIG. 32 is a cross-sectional view taken along section line 32-32 of FIG.31;

FIGS. 33 and 34 show a simplex fiber optic adapter in which one of theoptical fiber alignment devices of FIG. 32 has been incorporated; and

FIG. 35 shows the simplex fiber optic adapter of FIGS. 33 and 34 withfiber optic connectors inserted therein.

DETAILED DESCRIPTION

FIGS. 1-10 illustrate an optical fiber alignment device 20 in accordancewith the principles of the present disclosure. The optical fiberalignment device 20 is used to coaxially align and optically connecttogether two optical fibers such that optical transmissions can beconveyed from optical fiber to optical fiber. When first and secondoptical fibers are inserted into opposite ends of the optical fiberalignment device 20 along a fiber insertion axis 22, the optical fibersare guided to an orientation in which the optical fibers are coaxiallyaligned with one another with end faces of the optical fibers abuttingor in close proximity to one another. A mechanism can be provided withinthe optical fiber alignment device 20 for mechanically retaining theoptical fibers in an optically connected orientation. Thus, the opticalfiber alignment device 20 functions to provide a mechanical splicebetween the optical fibers inserted therein. In certain embodiments, anindex matching gel can be provided within the optical fiber alignmentdevice 20 for enhancing the optical coupling between the aligned opticalfibers retained within the optical fiber device 20. The optical fiberalignment device 20 can also include structure for cleaning the opticalfibers as part of the insertion process. Thus, the optical fibers can becleaned as part of the alignment process so as to be clean upon fullalignment and optical coupling of the optical fibers.

Referring to FIGS. 1-10, the optical fiber alignment device 20 includesan alignment housing 24 (e.g., a molded plastic housing) including firstand second ends 26, 28. The alignment housing 24 defines a fiberinsertion axis 22 that extends through the alignment housing 24 betweenthe first and second ends 26, 28. As shown at FIG. 7, the alignmenthousing 24 includes a fiber alignment region 30 at an intermediatelocation between the first and second ends 26, 28. The fiber alignmentregion 30 includes an alignment groove 32 that extends along the fiberinsertion axis 22. The alignment housing 24 also defines a pocket 34 atthe fiber alignment region 30 adjacent to the alignment groove 32. Thefirst end of the alignment housing 26 includes a first funnel 36 thatextends along the fiber insertion axis 22 for guiding a first opticalfiber (e.g., see the left optical fiber 100 at FIG. 19) into the fiberalignment region 30. The second end 28 of the alignment housing 24includes a second funnel 38 that extends along the fiber insertion axis22 for guiding a second optical fiber (e.g., see the right optical fiber100 at FIG. 19) into the fiber alignment region 30. The first and secondfunnels 36, 38 are configured to taper inwardly toward the fiberinsertion axis 22 as the first and second funnels 36, 38 extend into thealignment housing 24 toward the fiber alignment region 30. The taperedconfiguration of the funnels 36, 38 functions to guide the first andsecond optical fibers into coaxial alignment with the fiber insertionaxis 22 such that the optical fibers can be easily slid intoregistration with the alignment groove 32.

When the first and second optical fibers are inserted into the alignmenthousing 24 along the fiber insertion axis 22, alignment between theoptical fibers is provided by the alignment groove 32. In certainembodiments, the alignment groove 32 can have a curved transversecross-sectional shape (e.g., a semi-circular transverse cross-sectionalshape as shown at FIG. 9) and can be configured to receive the opticalfibers therein such that the optical fibers seat within the alignmentgroove 32. In such an embodiment, it will be appreciated that thetransverse cross-sectional shape of the alignment groove 32 complementsthe outer diameters of the optical fibers. In alternative embodiments,the alignment groove can have a transverse cross-sectional shape that isgenerally v-shaped (i.e., the alignment groove 32 can be a V-groove). Insuch an embodiment, the V-groove provides two lines of contact with eachof the optical fibers inserted therein. In this way, the line/pointcontact with the V-groove assists in providing accurate alignment of theoptical fibers.

It will be appreciated that the optical fibers inserted within theoptical fiber alignment device 20 are preferably preprocessed. Forexample, in certain embodiments, coatings of the optical fibers can bestripped from end portions of the optical fiber such that bare glassportions of the optical fibers are inserted within the fiber alignmentregion 30. In such embodiments, the alignment groove 32 is configured toreceive the bare glass portions of the optical fibers. In oneembodiment, the bare glass portions can have diameters ranging from120-130 microns and can be formed by glass cladding layers that surroundglass cores.

The optical fiber alignment device can also include cleaning structuresfor cleaning ferrule-less free end portions 100′ of the optical fibers100 during the alignment process. In one example, optical fiber cleaninglayers 500 (e.g., sheets, fabric layers, electrically charged layers,layers formed by electrospun fibers, self-healing layers, etc.) arepositioned adjacent the ends 26, 28 of the alignment housing. In oneexample, the optical fiber cleaning layers 500 are secured at majordiameters of the funnels 36, 38 by caps 502 mounted on the ends 26, 28of the alignment housing 24. In another example, the optical fibercleaning layers 500 are secured adjacent minor diameters of the funnels36, 38. During the fiber alignment process, the ferrule-less free endportions 100′ desired to be coupled together pass through (i.e.,penetrate, pierce, etc.) the optical fiber cleaning layers 500 as theferrule-less free end portions 100′ are inserted along the insertionaxis 22. In this way, end faces of the ferrule-less free end portions100′ are cleaned prior to be clamped within the alignment groove 32 toachieve co-axial alignment and optical coupling of the optical fibers100.

In one embodiment, the optical fiber cleaning layers 500 may include anelectrospun material. Electrospinning is a process well known in the artthat generally creates nanofibers through an electrically charged jet ofpolymer solution or polymer melt. The process of electrospinning resultsin the production of continuous fibers deposited as a non-woven fibrousmat or membrane by the application of an electric force. When thepolymer concentration is high, fibers can form from the utilization ofchain entanglement in polymer solutions or melts. In other words,electrospinning allows the fabrication of nanofibers from mixtures orsolutions, which have great potential for fabrication of non-woven fibermats. The materials to be electrospun will depend on the application.

In some implementations, the cleaning layers 500 are electrospun ontothe ends 26, 28 of the alignment housing 24 while the alignment housing24 is disposed within an adapter (e.g., adapters 60, 64, 66 of FIGS.13-19), a connector (e.g., connector 50 of FIGS. 11-12), or otherdevice. In certain implementations, the electrospinning process occursclose to the ends 26, 28 so that bending instabilities in the jet stillhave low amplitude. In certain implementations, a focusing electrode(e.g., a conductive ring) at the jet can be used to further decrease jetoscillations and focus the deposition of the fibers to the ends 26, 28of the alignment device 20. For example, the focusing electrode may bemaintained at a desired potential (e.g., a lower potential than thenozzle and a higher potential than a surface on which the fibers arespun) and tuned according to the flow of the fibers.

The electrospun material may include nanofibers that have a diameter ofbetween about 1-10 μm. In some implementations, the electrospun materialmay include polyurethane (PU). In certain implementations, theelectrospun material may include a thermoplastic PU. In an example, theelectrospun material includes a pure PU. In certain implementations, theelectrospun material includes PU blended with Polyethylene terephthalate(PET). In an example, the electrospun material includes a blend of PUand a low amount of PET (e.g., PU:PET 3:1, PU:PET 6:1, etc.). In oneembodiment, the electrospun material may be a contamination trappingbarrier of nanofibers that have charged ions configured for cleaningsurfaces of optical fibers.

In other implementations, the electrospun material may includePolycaprolactone (PCL) solution. PCL is a semi-crystalline aliphaticpolymer that can have a low glass transition temperature at −60° C., amelting temperature at about 60° C. In other examples, poly-L-lactide(PLLA) solution may be used to form the electrospun material. Due to thechiral nature of lactic acid, several distinct forms of polylactideexist (i.e., poly-L-lactide (PLLA) is the product resulting frompolymerization of L,L-lactide (also known as L-lactide)). PLLA can havea crystallinity of about 37%, a glass transition temperature betweenabout 55-65° C., a melting temperature between about 170-183° C. and atensile modulus between about 2.7-16 GPa. PLLA can be quite stable undereveryday conditions, although it may degrade slowly in humidenvironments at temperatures above its glass transition temperature. Instill other examples, the electrospun material may include a mixture ofboth PCL and PLLA. In still other implementations, other polymers may beused, such as, but not limited to, poly (ethylene oxide) (PEO), or amixture thereof with PU and/or PET.

In other implementations, other polymers can be used to form electrospunfibers. For example, in various other implementations, the electrospunfibers can be formed of Nylon 6,6, Polycarbonate, Polyacrylonitrile(PAN), Polystyrene, PMMA, Polyvinylidene fluoride (PVDF), PE, HDPE,Isotactic PP, Nylon12, Polyethylene naphthalate (PEN), and blends ormixtures of the same.

In this example, the electrospun material incorporates positive surfacecharges for electrostatic interaction with negatively charged dustparticles to clean an optical fiber. The thickness and/or density of thenanofibers in the electrospun material may determine the cleaningcapability and puncturing force to push a fiber through a membrane ofthe electrospun material. It is to be understood that the fibersurface/density may vary between samples of the same polymer. Inaccordance with another aspect of the disclosure, the electrospunmaterial may include apolar side chains on its surface for retaining oilmicelles thereon.

In some implementations, the electrospun cleaning layers 500 areconfigured to have a puncturing force of no more than 0.25 N. In certainimplementations, the electrospun cleaning layers 500 are configured tohave a puncturing force of no more than 0.1 N. In certainimplementations, the electrospun cleaning layers 500 are configured tohave a puncturing force of no more than 0.08 N. In certainimplementations, the electrospun cleaning layers 500 are configured tohave a puncturing force of no more than 0.07 N. In certainimplementations, the electrospun cleaning layers 500 are configured tohave a puncturing force of no more than 0.06 N. In certainimplementations, the electrospun cleaning layers 500 are configured tohave a puncturing force of no more than 0.05 N.

In some implementations, the electrospun cleaning layers 500 can have athickness of about 50 μm to about 500 μm. In certain implementations,the electrospun cleaning layers 500 can have a thickness of about 100 μmto about 400 μm. In certain implementations, the electrospun cleaninglayers 500 can have a thickness of about 150 μm to about 300 μm. In anexample, the electrospun cleaning layers 500 can have a thickness ofabout 200 μm.

The optical fiber alignment device 20 further includes structure forurging the optical fibers into contact with the fiber alignment groove32. In the depicted embodiment, the fiber optic alignment device 20includes first and second balls 40, 41 (i.e., fiber contact members)positioned within the pocket 34. The pocket 34 has an elongate directionthat extends along the fiber insertion axis 22 and the pocket 34functions to align the balls 40, 41 (e.g., spheres) along the fiberinsertion axis 22. The optical fiber alignment device 20 furtherincludes a biasing arrangement for urging the balls 40, 41 generallytoward the alignment groove 30. For example, the biasing arrangement canurge the balls 40, 41 in a direction transverse with respect to thefiber insertion axis 22. In the depicted embodiment, the biasingarrangement is shown including a clip 42 (e.g., a metal clip havingelastic properties) mounted (e.g., snap fitted) over the alignmenthousing 24 adjacent the fiber alignment region 30. The clip 42 has atransverse cross-sectional profile that is generally C-shaped. When theclip 42 is snapped over the alignment housing 24, the clip 42 functionsto capture the balls 40, 41 within the pocket 34. The clip 42 includesbiasing structures such as first and second springs 44, 45 forrespectively biasing the balls 40, 41 toward the alignment groove 32. Asdepicted, the springs 44, 45 are leaf springs having a cantileveredconfiguration with a base end integrally formed with a main body of theclip 42 and free ends that are not connected to the main body of theclip 42. In the depicted embodiment, the first spring 44 extends (e.g.,curves) from its base end to its free end in a generally clockwisedirection around the axis 22 and the second spring 45 extends (e.g.,curves) from its base end to its free end in a generallycounterclockwise direction around the axis 22. The springs 44, 45 aredefined by cutting or slitting the clip 42 so as to define slots in theclip 42 that surround three sides of each of the springs 44, 45.

In some implementations, a gel can be provided within the alignmentdevice 20 (e.g., within the pocket 34 and/or the fiber alignment groove32). In certain implementations, the gel facilitates alignment betweenoptical fibers at the alignment device 20. In certain implementations,the gel can be a thixotropic gel. In certain implementations, theelectrospun cleaning layers 500 can function as a scaffold to hold thegel within the alignment device 20. In an example, the electrospuncleaning layers 500 can retain the gel within the alignment device 20during de-mating (e.g., unplugging) of an optical fiber from thealignment device 20.

FIGS. 11 and 12 show the optical fiber alignment device 20 incorporatedinto a fiber optic connector 50 such as an SC connector. The connector50 includes a ferrule 52 supporting an optical fiber 54. A dust cap 56can be mounted over the interface end of the ferrule 52. The opticalfiber 54 includes a stub end 58 that projects rearwardly from theferrule 52 into the body of the connector 50. The stub end 58 isinserted within the first funnel 36 of the optical fiber alignmentdevice 20 and is shown pressed within the fiber alignment groove 32 bythe first ball 40. In other implementations, the alignment device 20 canbe integrally formed with the ferrule 52.

The connector 50 is optically connected to another fiber (i.e., a fiberto be terminated) by inserting the fiber to be terminated through therear end of the connector 50 and into the second funnel 38. As the fiberto be terminated is inserted into the second funnel 38, the fiber to beterminated is guided into alignment with the fiber insertion axis 22.Continued insertion of the fiber to be terminated causes the fiber toregister with the fiber alignment groove 32 and displace the second ball41 against the bias of the corresponding second spring 45. In this way,the spring biased balls 40, 41 assist in retaining the optical fibers inalignment along the alignment groove 32. In one embodiment, theconnector 50 can have mechanical field splice capabilities in which theconnector can be field spliced to an optical fiber by inserting theoptical fiber through the rear end of the connector 50 and into thefiber alignment device 20.

In some implementations, the fiber alignment device 20 includes one ormore optical fiber cleaning membranes 500. For example, in someimplementations, the fiber alignment device 20 has an optical fibercleaning membrane 500 at the second funnel 38 and does not include anoptical fiber cleaning membrane at the first funnel 36. In otherimplementations, the fiber alignment device 20 has an optical fibercleaning membrane 500 at each funnel 36, 38. In some implementations,the fiber cleaning membrane 500 is spun onto the alignment device 20. Inother implementations, the fiber cleaning membrane 500 is formed on asubstrate, removed from the substrate, and fixed (e.g., mechanicallyattached, glued, or otherwise coupled) to the alignment device 20.

In some implementations, the optical fiber cleaning layer 500 functionsto clean an optical fiber as the optical fiber is inserted into thefiber alignment device 20. In other implementations, the optical fibercleaning layer 500 functions to inhibit contamination of an opticalfiber after the optical fiber is cleaned and inserted into the fiberalignment device 20 (e.g., in a clean room or other sterileenvironment). In other implementations, the optical fiber cleaning layer500 functions to inhibit damage to an optical fiber after the opticalfiber is inserted into the fiber alignment device 20.

When the optical fiber is disconnected from the alignment device 20(e.g., upon discontinuation of service to a particular subscriber), thecleaning layer 500 recovers its original shape. For example, theelasticity of the electrospun fibers may cause the fibers to recovertheir shape upon removal of the optical fiber from the cleaning layer500. Accordingly, the cleaning layer 500 may be reused to clean and/orprotect another optical fiber subsequently inserted into the fiberalignment device 20.

FIGS. 13-16 and 31-32 illustrate duplex fiber optic adapters 60 adaptedfor receiving and optically connecting two pairs of fiber opticconnectors. In one embodiment, the connectors have an LP connector typeprofile/footprint. Two of the optical fiber alignment devices 20 aremounted within the duplex fiber optic adapter 60. In someimplementations, the adapter 60 includes an alignment device holder 25.In certain implementations, the adapter 60 includes a front portion anda rear portion that each include a part 25 a, 25 b of an alignmentdevice holder 25. The alignment device 20 can be disposed between (e.g.,enclosed within) the parts 25 a, 25 b of the alignment device holder 25.

The cleaning layers 500 are disposed within the adapter 60 at thealignment device 20. When fiber optic connectors are inserted withincoaxially aligned ports 62 of the fiber optic adapter 60, optical fibersof the fiber optic connectors enter the optical fiber alignment device20 through optical fiber cleaning layers 500 and the first and secondfunnels 36, 40 and are mechanically spliced at the fiber alignmentregion 30. In the example shown in FIGS. 13-16, the cleaning layers 500are disposed at an exterior of the alignment device holder 25. In somesuch implementations, the nozzle providing the electrospun fibers can beinserted into the adapter ports to spin the fibers onto the holder 25.In other such implementations, the cleaning layers 500 can be formed ona substrate and moved to the alignment device holder 25.

In the example shown in FIGS. 31 and 32, the cleaning layers 500 aredisposed at an exterior of the alignment device 20 (e.g., as shown inFIG. 7). In some implementations, a two-part adapter 60 and/or two-part25 a, 25 b alignment device holder 25 facilitates assembly of theadapter 60 with the cleaning layers 500. For example, in certainimplementations, the nozzle providing the electrospun fibers is insertedinto the holder parts 25 a, 25 b through openings at the seam 27 (FIG.16), thereby reducing a distance over which the fibers travel betweenthe nozzle and the surface on which they are spun.

In other implementations, the cleaning layers 500 can be formed on asubstrate and moved into the alignment device holder 25 through theopenings at the seam 27 before the alignment device 20 is disposed inthe holder 25. In certain implementations, the cleaning layers 500 areclamped or otherwise held between the alignment device 20 and thealignment device holder 25. In certain implementations, the cleaninglayers 500 are disposed within the holder 25, but glued or mechanicallyfastened to the alignment device 20.

FIGS. 17, 18, 33, and 34 show simplex fiber optic adapters 64, 66 havingthe same basic configuration as the duplex fiber optic adapter 60. Eachadapter 64, 66 includes an alignment device holder 25. In the exampleshown in FIGS. 17-18, the cleaning layers 500 are disposed at anexterior of the alignment device holder 25. In the example shown inFIGS. 33-34, the cleaning layers 500 are disposed at an exterior of thealignment device 20 and within the holder 25.

The simplex fiber optic adapters 64, 66 are the same except the simplexadapter 66 is provided with shutters 68. The shutters 68 flex open whenfiber optic connectors are inserted into corresponding ports of theadapter 66. When no connectors are inserted in the adapter 66, theshutter 68 inhibits dust or other contaminants from entering the fiberalignment device 20 within the interior of the adapter 66. The opticalfiber cleaning layers 500 provide a second level of protection forpreventing contaminants from entering the alignment device 20.

FIGS. 19 and 35 show the simplex fiber optic adapter 64 being used tooptically and mechanically couple two fiber optic connectors 69. In theexample shown in FIG. 19, the cleaning layers 500 are disposed at anexterior of the alignment device holder 25. In the example shown in FIG.35, the cleaning layers 500 are disposed at an exterior of the alignmentdevice 20 and within the holder 25.

In one example, the fiber optic connectors 69 can have an LP-connectortype footprint/profile/shape. The fiber optic connectors 69 includelatches 70 (e.g., resilient cantilever style latches) that engagecatches 71 of the fiber optic adapter 64. When the fiber opticconnectors 69 are inserted within coaxially aligned ports of the fiberoptic adapter 64, shutters 74 (see FIG. 20) of the fiber opticconnectors 69 are retracted (see FIG. 21) thereby exposing ferrule-lessfree ends 100′of the optical fibers 100 of the fiber optic connectors69. Continued insertion of the fiber optic connectors 69 into the portsof the fiber optic adapter 64 causes the end portions 100′ of theoptical fibers 100 to enter the optical fiber alignment device 20through cleaning layers 500 and the first and second funnels 36, 38. Theoptical fibers 100 slide along the insertion axis 22 and are broughtinto registration with the fiber alignment groove 30. As the opticalfibers 100 move along the fiber alignment groove 30, the optical fibers100 force their corresponding balls 40, 41 away from the alignmentgroove 32 against the bias of the springs 44, 45. The optical fibers 100slide along the alignment groove 32 until end faces of the opticalfibers 100 are optically coupled to one another. In this configuration,the springs 44, 45 and the balls 40, 41 function to clamp or otherwiseretain the optical fibers 100 in the optically coupled orientation.

The embodiments disclosed herein can utilize a dimensionally recoverablearticle such as a heat-recoverable tube/sleeve for securing/lockingoptical fibers at desired locations within the connector bodies and forattaching cable jackets and cable strength members to the connectors. Adimensionally recoverable article is an article the dimensionalconfiguration of which may be made substantially to change whensubjected to treatment. Usually these articles recover towards anoriginal shape from which they have previously been deformed, but theterm “recoverable” as used herein, also includes an article which adoptsa new configuration even if it has not been previously deformed.

A typical form of a dimensionally recoverable article is aheat-recoverable article, the dimensional configuration of which may bechanged by subjecting the article to heat treatment. In their mostcommon form, such articles comprise a heat-shrinkable sleeve made from apolymeric material exhibiting the property of elastic or plastic memoryas described, for example, in U.S. Pat. No. 2,027,962 (Currie); U.S.Pat. No. 3,086,242 (Cook et al); and U.S. Pat. No. 3,597,372 (Cook), thedisclosures of which are incorporated herein by reference. The polymericmaterial has been cross-linked during the production process so as toenhance the desired dimensional recovery. One method of producing aheat-recoverable article comprises shaping the polymeric material intothe desired heat-stable form, subsequently crosslinking the polymericmaterial, heating the article to a temperature above the crystallinemelting point (or, for amorphous materials the softening point of thepolymer), deforming the article, and cooling the article while in thedeformed state so that the deformed state of the article is retained. Inuse, because the deformed state of the article is heat-unstable,application of heat will cause the article to assume its originalheat-stable shape.

In certain embodiments, the heat-recoverable article is a sleeve or atube that can include a longitudinal seam or can be seamless. In certainembodiments, the tube has a dual wall construction including an outer,heat-recoverable annular layer, and an inner annular adhesive layer. Incertain embodiments, the inner annular adhesive layer includes ahot-melt adhesive layer.

In one embodiment, the heat-recoverable tube is initially expanded froma normal, dimensionally stable diameter to a dimensionally heat unstablediameter that is larger than the normal diameter. The heat-recoverabletube is shape-set to the dimensionally heat unstable diameter. Thistypically occurs in a factory/manufacturing setting. The dimensionallyheat unstable diameter is sized to allow the heat-recoverable tube to beinserted over two components desired to be coupled together. Afterinsertion over the two components, the tube is heated thereby causingthe tube to shrink back toward the normal diameter such that the tuberadially compresses against the two components to secure the twocomponents together. The adhesive layer is preferably heat activatedduring heating of the tube.

According to one embodiment, the heat-recoverable tube may be formedfrom RPPM material that deforms to a dimensionally heat stable diametergenerally at around 80° C. RPPM is a flexible, heat-shrinkable dual walltubing with an integrally bonded meltable adhesive liner manufactured byRaychem. According to another embodiment, the heat-recoverable tube 56may be formed from HTAT material that deforms to a dimensionally heatstable diameter generally at around 110° C. HTAT is a semi-flexible,heat-shrinkable tubing with an integrally bonded meltable adhesive innerlining designed to provide moisture proof encapsulation for a range ofsubstrates, at elevated temperatures. HTAT is manufactured by Raychemfrom radiation cross-linked polyolefins. The inner wall is designed tomelt when heated and is forced into interstices by the shrinking of theouter wall, so that when cooled, the substrate is encapsulated by aprotective, moisture proof barrier. According to one embodiment, theheat-recoverable tube may have a 4/1 shrink ratio between thedimensionally heat unstable diameter and the normal dimensionally heatstable diameter.

Referring again to FIGS. 20 and 21, the fiber optic connector 69 is partof a fiber optic assembly that includes a fiber optic cable 112terminated to the fiber optic connector 69. The fiber optic cable 112includes the optical fiber 100 and an outer jacket 116. In certainimplementations, the fiber optic cable 112 includes a strength layer 118positioned between the fiber 100 and the outer jacket 116. In certainimplementations, the fiber optic cable 112 includes a buffer tube 117(e.g., a buffer layer having an outer diameter ranging from 600-1000microns (e.g., about 900 microns)) that surrounds the optical fiber 100.The optical fiber 100 can also include a coating layer 113 thatsurrounds a bare glass portion 111. In one example, the coating layer113 can have an outer diameter ranging from 230-270 microns and the bareglass portion 111 can have a cladding layer having an outer diameterranging from 120-130 microns and a core having a diameter ranging from5-15 micron. In an example, the optical fiber 100 has a diameter ofabout 250 microns. Other examples can have different dimensions. Thestrength layer 118 can provide tensile reinforcement to the cable 112and can include strength members such as reinforcing aramid yarns.

The fiber optic connector 69 includes a main connector body 122 having afront mating end 124 and a rear cable terminating end 126. Anelectrically conductive (e.g., metal) rear insert 130 is secured (e.g.,press fit within) the rear cable terminating end 126 of the connectorbody 122. The optical fiber 100 extends from the fiber optic cable 112forwardly through the main connector body 122 and has a ferrule-less endportion 100′ that is accessible at the front mating end 124 of theconnector body 122. Adjacent the rear cable terminating end 126 of theconnector body 122, the optical fiber 100 is fixed/anchored againstaxial movement relative to the connector body 122. For example, theoptical fiber 100 can be secured to a fiber securement substrate 119 bya shape recoverable article 121 (e.g., a heat shrink sleeve having aninner layer of hot melt adhesive). The fiber securement substrate 119can be anchored within the rear insert 130. The rear insert 130 can beheated to transfer heat to the shape recoverable article thereby causingthe shape recoverable article 121 to move from an expanded configurationto a fiber retaining configuration (e.g., a compressed configuration).The shape recoverable article 121 and the fiber securement substrate 119function to anchor the optical fiber 10 against axial movement relativeto the connector body 122. Thus, when an optical connection is beingmade, optical fiber cannot be pushed from inside the connector body 122back into the fiber optic cable 112.

A fiber buckling region 190 (i.e., a fiber take-up region) is definedwithin the connector body 122 between the fiber anchoring location atthe rear of the connector body 122 and the front mating end 124 of theconnector body 122. When two connectors 69 are coupled together withinone of the adapters 64 (as shown at FIG. 19), the end faces of theferrule-less end portions 100′ of the optical fibers 100 abut oneanother thereby causing the optical fibers 100 to be forced rearwardlyinto the connector bodies 122. As the optical fibers 100 are forcedrearwardly into the connector bodies 122, the optical fibers 100buckle/bend within the fiber buckling regions 190 (see FIGS. 19, 21 and32) since the fiber anchoring location prevents the optical fiber 100from being pushed back into the optical cable 112. The fiber bucklingregions 190 are designed so that minimum bend radius requirements of theoptical fibers 100 are not violated. In one example, the fiber bucklingregions are sized to accommodate at least 0.5 millimeters or at least1.0 millimeters of rearward axial movement of the optical fibers 100,102. In one embodiment, the fiber buckling regions 190 have lengths from15-25 millimeters. Fiber alignment structures 189 can be provided at thefront mating ends 124 of the connectors 69 for providing rough alignmentof the ferrule-less end portions 100′ along insertion axes of theconnectors 69. In this way, the ferrule-less end portions 100′ arepositioned to slide into the first and second funnels 36, 38 of thealignment device 20 when the connectors 69 are inserted into a fiberoptic adapter such as one of the adapters 60, 64 or 66.

Referring still to FIGS. 20 and 21, the fiber securement substrate 119can be loaded into the rear insert 130 through a front end of the rearinsert 130. A front retention structure 123 (e.g., a flange, lip, tab orother structure) of the fiber securement substrate 119 can abut, matewith, interlock with or otherwise engage a front end of the insert 130.The rear insert 130 can be press fit within the rear end of theconnector body. As used herein, the front end of the connector is themating end where the ferrule-less end portion 100′ is accessible, andthe rear end of the connector is the end where the cable is attached tothe connector body.

The shutter 74 of the fiber optic connector 69 is movable between aclosed position (see FIGS. 22 and 23) and an open position (see FIGS. 24and 25). When the shutter 74 is in the closed position, the ferrule-lessend portion 100′ of the optical fibers 100 is protected fromcontamination. When the shutter 74 is in the open position, theferrule-less end portion 100′ is exposed and capable of being accessedfor making an optical connection. The shutter 74 includes a front coverportion 75, a top portion 77 and a lever portion 79 that projectsupwardly from the top portion 77. The shutter 74 pivots between the openand closed positions about a pivot axis 73.

FIG. 26 shows a converter 300 in accordance with the principles of thepresent disclosure for converting the ferrule-less connector 69 to aferruled connector. In the depicted embodiment, the ferruled connectorhas a SC-type footprint/shape/profile that mates with an SC-type fiberoptic adapter 302 configured for interconnecting two ferruled SC-typeconnectors. As shown at FIGS. 27 and 28, the converter 300 includes anouter housing 304 (e.g., an SC-release sleeve that is pulled back todisengage the converter 300 from a standard SC adapter), a dust cap 306,an inner housing 308, a ferrule assembly 310 including a ferrule 311 anda ferrule hub 312 (i.e., a ferrule base) mounted to a back end of theferrule 311, the fiber alignment device 20, a spring 314 for biasing theferrule assembly 310 in a forward direction, and a retention cap 316 forsecuring the fiber alignment device 20 to the ferrule hub 312. As shownat FIG. 29, an optical fiber stub 320 is potted (e.g., adhesivelysecured) with a central bore 322 defined axially through the ferrule311. The optical fiber stub 320 has a polished end 324 positionedadjacent a front end face 326 of the ferrule 311. The dust cap 306 canbe mounted over the front end face 326 to protect the polished end 324of the optical fiber stub 320 from damage or contamination. The opticalfiber stub 320 includes a rear portion 328 that projects rearwardly froma rear end 330 of the ferrule 311. The rear portion 328 of the opticalfiber stub 320 extends through the first funnel 36 of the optical fiberalignment device 20 and is shown pressed within the fiber alignmentgroove 32 by the first ball 40.

In certain embodiments, the spring 314 can be a spring washer such as aBelleville washer or a wave washer. In this way, the spring can provideits biasing function while being relatively compact in an axialdirection.

Referring to FIGS. 28 and 29, the inner housing 308 includes a front end332 and a rear end 334. The front end 332 forms a plug interface endcompatible with a fiber optic adapter such as a standard SC adapter 302.The ferrule assembly 310 mounts with the inner housing 308 adjacent thefront end 332 of the inner housing 308. The front end face 326 of theferrule projects forwardly beyond the front end 332 of the inner housing308 so as to be accessible for connection to another fiber opticconnector. The outer housing 304 snaps over the inner housing 308 andhas a limited range of axial movement relative to the inner housing 308.When front end 332 of the inner housing 308 is inserted into the fiberoptic adapter 302, the ferrule 311 fits within an alignment sleeve ofthe fiber optic adapter 302 and latches of the adapter 302 engage upperand lower catches 338 of the inner housing 308 to lock the front end 332of the inner housing 308 within the adapter 302. To release the innerhousing 308 from the adapter 302, the outer housing 306 is retractedrelative to the inner housing 308 such that upper and lower rampsurfaces 336 of the outer housing 306 disengage the latches of theadapter 302 from the catches 338 so that the inner housing 308 can bewithdrawn from the adapter 302.

The ferrule assembly 310 and the spring 314 can be retained at the frontend 332 of the inner housing 308 by a locking clip 340. The locking clip340 can be side loaded into the inner housing 308 and captures thespring 314 and the ferrule hub 312 within the front end 332 of the innerhousing 308. For example, the ferrule hub 312 and the spring 314 arecaptured between an inner shoulder 342 of the inner housing 308 and thelocking clip 340. In this way, the spring biases the ferrule assembly310 in a forward direction. During a connection, the ferrule assembly310 can move rearwardly relative to the inner housing 308 against thebias of the spring 314 as the front end face 326 of the ferrule 311contacts the end face of the ferrule of a mating connector insertedwithin the adapter 302. The locking clip 340 is preferably lockedagainst axial movement relative to the inner housing 308. The hubassembly 310 has a range of axial movement relative to the inner housing308 that is defined between the inner shoulder 342 and the locking clip340. The alignment device 20 is mounted to the hub assembly 310. Thus,the alignment device 20 is carried with the hub assembly 310 as the hubassembly 310 moves axially relative to the inner housing 308. In oneexample, at least a portion of the alignment device fits inside aportion of the ferrule hub 312. For example, the ferrule hub 312 candefine a receptacle 344 that receives one end of the alignment device20. The retention cap 316 can snap-fit to a back end of the ferrule hub312 and is configured to attach the alignment device 20 to the ferrulehub 312.

In use, the connector 69 is inserted into the converter 300 through therear end 334 of the inner housing 308. When inserted within the innerhousing 308, the ferrule-less end portion 100′ of the optical fiber 100of the connector 69 slides through the optical fiber cleaning layer 500into the alignment device 20 and is co-axially aligned with andoptically connected to the optical fiber stub 320 supported by theferrule 311. The ferrule-less end portion 100′ can extend through thesecond funnel 38 of the alignment structure 20 and can be pressed intothe alignment groove 32 by the ball 41. The inner housing 308 caninclude structure for retaining the connector 69 within the rear end334. For example, the inner housing 308 can include a catch 350 thatengages the latch 70 of the connector 69. The latch 70 is connected tothe main body 122 of the connector 69 by an interconnect piece 352. Whenthe connector 69 is latched in the inner housing 308, the catch 350opposes a latching surface 351 of the latch 70 and the rear end 334opposes the interconnect piece 352 to limit axial movement between theconnector 69 and the inner housing 308 in both inner and outer axialdirections. By depressing a rear end 354 of the latch 70, the latchingsurface 351 can be disengaged from the catch 350 to permit removal ofthe connector 69. Contact between the rear end 334 of the inner housing308 and the interconnect piece 352 limits the distance the connector 69can be inserted into the inner housing 308. It will be appreciated thatthe inner housing 308 also includes structure for: a) moving thelatching arms 206 of the connector 69 from the latching position to therelease position; and b) moving the shutter 74 of the connector 69 fromthe closed position to the open position. For example, as disclosed withregard to the fiber optic adapter 60, the inner housing 308 can includethe release rails 230 and the shutter actuation post 234.

In other implementations, the optical cleaning membrane 500 can be usedwith optical fibers held (at least partially) by optical ferrules. Insome such implementations, the optical cleaning membrane 500 may wipeacross a portion of the ferrule (e.g., the tip of the ferrule) toperform a cleaning action. In other such implementations, a portion ofthe ferrule may pierce the optical cleaning membrane 500 to perform acleaning action. In other such implementations, a portion of the opticalfiber may extend past the tip of the ferrule. The portion of the opticalfiber may pierce the cleaning membrane 500 as described above.

The above specification, examples and data provide a completedescription of the manufacture and use of the composition of theinvention. Since many embodiments of the invention can be made withoutdeparting from the spirit and scope of the invention, the inventionresides in the claims hereinafter appended.

LIST OF REFERENCE NUMERALS AND CORRESPONDING FEATURES

-   20 optical fiber alignment device-   22 fiber insertion axis-   24 alignment housing-   25 alignment device holder-   25 a, 25 b parts of alignment device holder-   26 first ends-   27 seam-   28 second ends-   30 fiber alignment region-   32 alignment groove-   34 pocket-   36 first funnel-   38 second funnel-   40 first ball-   41 second ball-   42 clip-   44 first spring-   45 second spring-   50 connector-   52 ferrule-   54 optical fiber-   56 dust cap-   58 stub end-   60 adapter-   62 ports-   64 adapter-   66 adapter-   68 shutters-   69 fiber optic connectors-   70 latches-   71 catches-   73 pivot axis-   74 shutter-   75 front cover portion-   77 top portion-   79 lever portion-   100 optical fiber-   100′ ferrule-less free end portions-   111 bare glass portion-   112 fiber optic cable-   113 coating layer-   116 outer jacket-   117 buffer tube-   118 strength layer-   119 fiber securement substrate-   121 shape recoverable article-   122 main connector body-   123 front retention structure-   124 front mating end-   126 terminating end-   130 rear insert-   189 fiber alignment structures-   190 fiber buckling region-   206 latching arms-   230 release rails-   300 connnecter-   302 fiber optic adapter-   304 outer housing-   306 dust cap-   308 inner housing-   310 ferrule assembly-   311 ferrule-   312 ferrule hub-   314 spring-   316 retention cap-   320 optical fiber stub-   322 central bore-   324 polished end-   326 front end face-   328 rear portion-   330 rear end-   332 front end-   334 rear end-   336 ramp surfaces-   338 catches-   340 locking clip-   342 inner shoulder-   344 receptacle-   350 catch-   351 latching surface-   352 interconnect piece-   354 rear end-   500 optical fiber cleaning layers-   502 caps

What is claimed is:
 1. An optical fiber alignment system comprising: analignment device extending between first and second fiber insertionregions, the alignment device defining an alignment groove that extendsbetween the first and second fiber insertion regions, the alignmentgroove defining a fiber insertion path between the first and secondfiber insertion regions; an engagement member disposed opposite thealignment groove; a biasing member that extends over the engagementmember so that the engagement member is disposed between the biasingmember and the alignment groove, the biasing member applying a springbias to the engagement member to bias the engagement member towards thealignment groove sufficient to at least partially close the fiberinsertion path, whereby an optical fiber displaces the engagement memberagainst the spring bias to open the fiber insertion path when theoptical fiber is moved within the alignment groove along the fiberinsertion path; and gel disposed within the alignment device.
 2. Theoptical fiber alignment system of claim 1, wherein the alignment deviceis elongate between the first and second fiber insertion regions.
 3. Theoptical fiber alignment system of claim 1, wherein the alignment groovehas a curved transverse cross-sectional shape.
 4. The optical fiberalignment system of claim 1, wherein the biasing member includes acantilevered beam.
 5. The optical fiber alignment system of claim 1,wherein the biasing member holds the engagement member at the alignmentdevice.
 6. The optical fiber alignment system of claim 5, wherein theengagement member is disposed within a pocket defined by the alignmentdevice; and wherein the biasing member is mounted to the alignmentdevice to extend across the pocket.
 7. The optical fiber alignmentsystem of claim 1, wherein the alignment groove defines a matinglocation at which end faces of optical fibers inserted at the first andsecond fiber insertion regions contact each other, and wherein thebiasing member is offset from the mating location.
 8. The optical fiberalignment system of claim 1, wherein the biasing member is one of aplurality of biasing members.
 9. The optical fiber alignment system ofclaim 8, wherein the plurality of biasing members include cantileveredsprings extending from a common body.
 10. The optical fiber alignmentsystem of claim 9, wherein a first of the cantilevered springs extendsin a first direction and a second of the cantilevered springs extends ina second direction that is opposite the first direction.
 11. The opticalfiber alignment system of claim 8, wherein the engagement member is oneof a plurality of engagement members.
 12. The optical fiber alignmentsystem of claim 11, wherein each biasing member applies a spring bias toone of the engagement members.
 13. The optical fiber alignment system ofclaim 1, wherein the engagement member is a separate piece from thealignment device.
 14. The optical fiber alignment system of claim 13,wherein the engagement member includes a ball.
 15. The optical fiberalignment system of claim 1, wherein the first and second fiberinsertion regions define insertion passages that taper inwardly towardsthe fiber insertion path as the insertion passages extend into thealignment device.
 16. The optical fiber alignment system of claim 1,wherein the alignment groove has a v-shaped transverse cross-section.17. The optical fiber alignment system of claim 1, wherein the biasingmember crosses the fiber insertion path.
 18. The optical fiber alignmentsystem of claim 1, wherein the gel is a thixotropic gel.
 19. The opticalfiber alignment system of claim 1, wherein the alignment device, theengagement member, and the biasing member are disposed within a body ofan optical adapter, the body being configured to receive and releasablyretain a respective optical plug connector at opposite ends of the body.20. the optical fiber alignment system of claim 19, wherein the body ofthe optical adapter is configured to receive and releasably retain aplurality of optical plug connectors at each of the opposite ends of thebody; and wherein the body holds a plurality of alignment grooves, aplurality of engagement members, and a plurality of biasing members.